Plaster board



Sept. 22p 1931. c, w, UTZMAN 1,824,245

PLAsTER BOARD Filed Aug. 12, 1922 Patented Sept'. 22, 1931 UNITED STATESPATENT OFFICE CLARENCE W. 'UTZMAN, 0F CHICAGO, ILLINOIS, AS-SIGNOR, BYMESNE ASSIGNMENTS, T0 UNITED STATES GYPSUM COMPANY l PLASTER BOARDApplication filed August 12, 1922,. Serial No. 581,361.

This inventionvrelatesto plaster board or the like, and to the method ofmaking it. Plaster board is usually employed as a wall covering insubsti ution for lath and plaster.

Among other objects, the invention is in# tended to supply a protectededge for plasterboard which shall be of neat appearance, secure anddurable.

The invention resides in the novel construcw tions, combinations andmethods, hereinafter described or claimed, for carrying out the abovestated object and such other objects as will hereinafter appear.

In the drawings:

Fig. 1 is a fragmentary perspective showing an end of the plaster boardand a protected edge thereof embodying this invention,

Fig. 2 is a cross section through the prof 30 tected edge on the lineQ-Q of Fig. 1, and

Figs. 3 and 4 respectively, are sections similar to Fig. 2 butshowingmodifications of the form shown in Fig. 2.

' Referring to the drawings, the body 5 of the plaster board is ofplaster or the like,

with or without admixture of other ingredients. The body 5 has a topcover sheet 6 and a bottom cover sheet 7, preferably of heavy paper orthe like adhered to the faces of the body. One of the covering sheets,the sheet- 7 in the illustrative instance, is folded at its mar in 8 soas substantially to cover the edge o the plaster body 5. To facilitatethe folding of the margin 8, the sheet 7 is preferably scored. at9`a1ong theline upon which the margin is to be folded.

The extremeedge of the margin 8 may be located in any desired relationto the edge of the' top sheet 6. For instance it is not indispensablethat the edge of the margin 8 stances, and it is one of the objects ofthis invention to provide an eicient mechanical bond between the margin8 or its equivalent contact with the top sheet 6,. or that the marthemargin 8 surrounding the aperture.

Thus anl integral part 11 of the body material may be made to engage theouter face of the margin 8 to hold it securely to the body. n

To enhance and facilitate the result just described, the outer surfaceof the margin 8 may be concaved into a cup-like form substantially.concentric withthe aperture, so that the plaster body material mayproject through the aperture and extend. into the cup-like concayity,while not projecting materially beyond the normal plane of the outerface of the lmargin 8. This eiiect is illustrated in perspective in Fig.1.

Fig. Sillustrates a slightly different form for producing the samegeneral result, the

margin 8 being shown as penetrated to form a more or less raggedaperture 12 therein having burrs 13, so to speak, engaging with theplaster of the body material. vHere again some of the material of thebody makes an anchorage against outwardly dispos'ed parts of the margin8.

In Fig. 4 the aperture 14 is formed so as to -leave a substantial tongue15 to be engaged by the plaster body material, part of which may alsoanchor against the outwardly disposed shoulder 16 of the tongue.

It will be observedthat the various exemplary deformations of the margin8 provide cllicient anchoring means located at intervals lengthwise themargin and occurring as frequently as may b'e deemed necessary to holdor assist in holding the margin in proper place. While the margin 8 isdeformed at intervals for the purposes described, the margin between thedeformations mayvremain intact and smooth to cover and protect the 100edge of the board on that area over which the margin extends. Of coursethe details of construction described. may be variously modified. In theprocess of making the plaster board, the body material in a suitableplastic state may be spread to a uniform thickness or layer on thebottom covering sheet 7, the margin 8 of which may be folded upon and inadhering contact with the edge of the plastic layer; and the topcovering sheet 6 may then be applied; both sheets adhering to the,

plastic body material substantially throughout the width of the boardbeing manufactured. The aforesaid deformations in the margin 8 may, ifdesired, 'be preliminarily formed, in which event said deformations maybe caused to embedin or interengage with the plastic body material by,effecting a slight spreading of the material when the margin is foldedaga-inst the edge thereof; or the said deformations may be made in themargin 8 after the margin is folded upon the edge of the body materialand while the lat- .ter is still in plastic state, so as toA allow theplastic material to spread through the .apertures of the margin andengage against the outwardlydisposed shoulders thereof, to providesecure anchorages when the plastic material becomes set. The processmaybe conveniently carried out by- .continuously passing upper and lowercovering sheets and an intervening layer of plastic body material betwensuitable spreading rolls and lateral devices for turning up the marginsof the lower sheet and pressing them a ainst the edges of the plasticmaterial, and eforming the margins to secure anchorages inthe plasticmaterial as aforesaid. f Having described my invention, I claim: l.-Aplaster board comprising, in combiperforations.

along aline substantially coincident with the 5. A plaster boardcomprising in combi` nation a body of plaster or the like; normally'imperforate fibrous cover material covering the opposite faces of saidbody and adhering thereto; and a margin of said cover mav terialfoldedover an edge of the body .and being rendered perforate by a series ofopenings, therein into which the material of the body extends, therebyproviding anchorages with, the plaster body, said margin beingconstructed and arranged to expose a substantial area of the plasterbody at the edge Qf the board. ,i

In testimony whereof, I have signed my name to this specification.

CLARENCE W. UTZMAN.

nation, a body of plaster or the like covering material on the face ofsaid body; and alfolded cover sheet margin on an edge -of said body andanchored thereto by portions of the body material protruding throughapertured portions of the margin.

2. A plaster board comprising a.body of plaster interposed betweensheets of'fibrous material, one of said sheets having a.` perforatedmarginal portion folded over upon an edge of said body.

I3. A plaster board comprising a body of plasterinterposed betweensheets of fibrous material, one of said sheets having a marginal portionfolded over upon an edge of said body and terminating short of the fullwidth of said edge, said marginal portion having a plurality ofperforations extending longitudinally thereof.l f Y 4. A plaster boardcomprising a plaster body interposed between covering sheets of fibrousmaterial, one of said sheets having a perforated marginal portionadapted to b e 65 folded over the edge surface of said body,

